Christmas Market Trip 2024

Remember the Xmas markets are a German tradition, I would spend more time in Germany. I assumed you checked the opening and closing dates of each market?
You could fly open jaw, multi-city, into Amsterdam and out of Frankfurt or Munich.
I highly recommend Stuttgart and Esslingen, the latter which is one of the most fun markets I have ever been to.
And to mix it up more, there's the spectacular markets in Strasbourg , France!
As soon as you do have an itinerary, book lodging asap. When I planned my trip, some hotels were fully booked by June, especially for the weekends.
I really like Rothenburg, and find the town very charming, but the Xmas market is very small.
Many of your questions are answered in my 2019 Trip Report below.
Good luck and have fun planning! The markets are magical!

https://community.ricksteves.com/travel-forum/trip-reports/christmas-markets-switzerland-france-germany-2019

I agree with Pat. I would probably cut Rotterdam and Hague and try and work more time into Germany. If you had 3 nights in Nuremburg you could spend a day in Regensberg and hit the Thurn and Taxis market there which is supposed to be quite wonderful.

Make sure you check those closing dates for the markets. Many markets will be closing on the 22nd or 23rd.
Everything in Germany basically shuts down on the 24th around 14:00. This includes 98% of the restaurants and museums. This is a day when I would want reservations in a nice hotel for dinner. The 25th and 26th are official holidays, so stores will be closed, but restaurants will be doing a booming business if they are open. Museums may or may not be open, so it is good to check.

Candidly the Christmas Market portion of your visit ends on 23 December, which as several noted is the traditional end date….for the most part. You have a lot of travel…in and out of hotels, on and off trains. That takes up a lot of time away from your primary goal. The selection of Christmas markets is nearly endless and you don’t necessarily need to track all over Germany to have a varied experience.

Do less enjoy more!

The Christmas Markets will be pretty much done by time you get to Köln. I assume the trip is about much more than the markets themselves.

Dress in layers and pack light. The winter could be cold or mild. LL Bean and REI have thin, light long underwear layers that add warm well above their weight and bulk in your luggage. Take some layers like fleece. I find 35-40 degrees and rain to be the toughest weather to handle on a Christmas Market trip: take a rain shell that works.

The trick about transferring from one train to another is to be at the door ready to exit when the the train pulls into the station. If you wait till the train stops to gather your luggage, you will find yourself struggling to get off while others are getting on the train. It can be like swimming upstream.

Most places take credit cards but we also carry cash for small restaurants and all those food booths at the markets.

You are making some short stays in large cities. You may not have enough time to get oriented and see much. We would stay in fewer and probably smaller places. You are the best judge about what would work for you.